One-fifth of Medicare nursing home patients with advanced Alzheimer's or other dementias were sent to hospitals or other nursing homes for questionable reasons in their final months, often enduring tube feeding and intensive care that prolonged their demise, a new study found.

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Nursing homes may feel hospital care is warranted when a frail, elderly patient develops swallowing problems, pneumonia or a serious infection, but researchers suspect a different motive for many transfers: money. Medicare pays about three times the normal daily rate for nursing homes to take patients back after a brief hospitalization.

"I think that's unfortunately a factor in what's happening here," said Dr. Joan Teno, a palliative care physician and health policy professor at Brown University. "A lot of this care just feels like in and out, in and out. You really have to question, is the health care system doing a good job or not."

She is a co-author of the study, published in Thursday's New England Journal of Medicine and done with researchers from Harvard University and Dartmouth Medical School.

Among the nearly 475,000 patients studied, 19 percent were moved for questionable reasons. The study provided no evidence that money motivated such transfers or that there was wrongdoing involved. However, the large variation that researchers saw from state to state suggests money may be playing a role.

Rates of such transfers varied from 2 percent in Alaska to more than 37 percent in Louisiana. In McAllen, Texas, 26 percent of study participants had multiple hospitalizations for urinary infections, pneumonia or dehydration — conditions that usually can be treated in a nursing home. That compares to just 1 percent of patients in Grand Junction, Colo.

The researchers used Medicare records from 2000 through 2007 to identify "burdensome" transitions of care: moving patients in the last three days of life, moving them multiple times in the last three months of life, or moving them so they landed in a new nursing home afterward.

Medicaid pays on average $175 per day, depending on the state, for long-term care, but Medicare will pay three times that for skilled nursing care after a patient returns from three days or more in a hospital.

"If you have a nursing home that is operating on a margin, it adds up. It can be a tremendous incentive to hospitalize these people," Teno said.

Researchers found that patients who had a dubious transfer were more likely to have a feeding tube inserted, to spend time in intensive care in the last month of life, to have a severe bedsore or to be enrolled in hospice late (three days or less before they died).

Dubious transfers were more common with black patients, Hispanics and those without advance directives, legal documents spelling out care wishes.

The National Institute on Aging sponsored the study. One author consults for a nursing home system and owns stock in a long-term care information services company.

The study is important because more than 1.6 million Americans live in nursing homes, and nearly one-quarter of people admitted to one after hospitalization wind up back in the hospital within a month, Dr. Joseph Ouslander of Florida Atlantic University in Boca Raton and Dr. Robert Berenson of the Urban Institute in Washington, D.C., wrote in an editorial in the journal. Nursing homes may fear legal liability if they don't hospitalize a very sick patient, they wrote.

However, people with advanced dementia have a terminal condition.

"These are people who are unable to recognize their relatives, they're bed-bound and they're now usually having problems with swallowing. This is a population where the burdens of hospitalization often outweigh the possible benefits," Teno said. "These patients actually do better when they stay in a nursing home," where caregivers and surroundings are familiar, she said.

For families and nursing homes, "it may be difficult to recognize that in fact, this person is in the dying process," said Dr. Michael Malone, medical director of senior services for Aurora Health Care, a network of 15 hospitals in eastern Wisconsin. His 87-year-old father, Wendell Malone, died in January of advanced dementia in a nursing home that managed his care without frequent hospitalizations.

"It provided dignity, it provided comfort for the family," and let him stay in a place and with caregivers he knew, Malone said.

Beth Kallmyer, who runs programs for caregivers for the Alzheimer's Association, said the most important thing is to have a plan in place, with legal documents like "do not hospitalize" directives, before a nursing home has to make a decision about whether to hospitalize someone or instead focus on comfort care and not try to prolong life.

"When the time comes, the family will be able to say 'This is what dad wanted,'" Kallmyer said.

She and other experts offered these tips:

—Involve patients in planning their care while they're still able to do so, and make sure wishes like "do not resuscitate" or "do not call 911" are spelled out in legal documents.